WFTF piston for 2019

[Scotchmo]

I'm getting ready for next year with a little more emphasis on WFTF. Though I still plan on shooting in Hunter and Open some times.

I've made too many changes at times and then it's harder to evaluate what is actually helping. So I'm taking it a step at a time. OK - a couple steps at a time.

After the recent 2018 National match, the first thing I did was shorten the gun about 3" so that it would fit in a case that is legal on all airlines as checked baggage. I will be flying to a match at least one time next year. My rig was at 12 lbs originally, which is a good compromise for a 12fpe piston gun. I lost about 1 lb off the end of the muzzle when I shortened it and decided that the resulting 11 lb total weight was too low. I shot it just little bit that way. Lighter weight makes a piston gun harder to control and it's harder on scopes. I've seen piston FT guns weighing a lot more so I decided to add some extra weight during process. First I added an Anschutz style rail. The rail addition adds nothing by itself, but it gives me a convenient way to add other weights and accessories to test out.





The C-channel added about 4.2lb. and the ram mount about 1.5 lb. bringing the total to about 17 lb. I can swing the Ram mount forward and rest the flat channel on my knee for most shots, same way as I shot before. If I need some extra elevation for high angles or obscured targets, I can extend the hamster a few inches. That might also help on standing and kneeling shots.



Our club had an FT match in Cambria last Sunday. I tried the QB58 with just the C-channel (no hamster). I was also testing a new scope with higher mounts and new dope. I got the same score as I did the last time I shot in the old configuration on that same course. So far, so good. I'll add the hamster into the mix for the next match.

[Calmark]

This is a good time prior to the 2019 FT season to be testing out physical changes to and new techniques relating to your spring gun and scope. 

The Anschutz type rail will be very handy to easy application and removal of accessories such as the hamster.  I've often thought it would be nice to have one on my HW97, TX200 and other piston guns to add versatility like yours now has. 

It will bring big peace of mind to minimize a loss of your QB58 while flying now that you can have it with you on the plane while traveling.  Shortening it was a good move and you have plenty of time to get the weight and balance figured out. 

I really do think the hamster will prove to be helpful, especially if you need extra height on targets at a steep incline.  I have a similar RAM mount screwed onto the stock of my TX and I think it has been an advantage when shooting offhand and not just while seated.  Let us know how the extra weight of the C-channel and hamster help or hinder shooting in future matches.  I predict you'll find an increase in scores once you adapt to the new add-ons. 

 

[Scotchmo]

This is a good time prior to the 2019 FT season to be testing out physical changes to and new techniques relating to your spring gun and scope....

I plan on spending the next two months doing just that.

I ordered a bunch of steel and aluminum including an aluminum channel identical to the steel piece. I'm going to try adding a carry handle so that I won't need a case or gun caddy to tote the gun between lanes. And also looking at adding a butt-hook/butt-weight. All parts can be swapped for aluminum or steel to experiment with the weight/balance. Once fully configured, overall weight can be easily varied between 16lbs and 24lbs total. With weight distributed as needed.

[Calmark]

I've wanted to experiment with butt hooks during this off season to see if I can add some more stability while shooting wftf.  I've also thought of adding weight to the rear of a wftf gun to see how it would handle.  I have a Weihrauch HW55 target rifle somebody poured roughly a pound of lead into a hollowed out section of the butt stock.  Coupled with the ~1lb barrel sleeve, it makes for terrific balance and helps absorb recoil of course.

I'm going to bet your gun will be much less affected by recoil at the 24lb mark.  That weight might be worth putting up with if the addition of a hamster, butt hook and getting the balance right allows it to be usable in the forced position lanes.  It occured to me you can also make a new barrel weight that is longer than you currently have and slide it farther back on the barrel.  That might change harmonics, poi, etc, but is another option to add weight up front if desired.

I'm on the lookout for a QB58 for modifying as well this winter and have using it in mind for some fun in FT next season.  Its a nice compact, side lever with sliding compression tube that allows direct loading of pellets like I prefer.  It also lends itself well to experimentation since the basic gun tends to cost under $100.

[Scotchmo]

...It occured to me you can also make a new barrel weight that is longer than you currently have and slide it farther back on the barrel.  That might change harmonics, poi, etc, but is another option to add weight up front if desired....

I was going to do that when I shortened the gun. I was going to remove it and bore it out deeper, then slide it on farther. But I had used a bunch of loc-tite and setcrews when I last installed that weight. I has not moved in years. I tried getting it off with a heat gun. It was not budging, so decided to just lop a couple inches from the weight instead.

[Scotchmo]

I shot my QB58 at last Sunday's CASA FT match. I had the weight up to 21 lbs. I shot well enough but I really did not like dealing with that much weight. Very light recoil but balance is not yet right.

I was also testing my new scope wheel (with extra data columns). And my built in caddy/handle. Both worked well. I usually case my guns between lanes but am looking for ways to speed things up. But I don't like seeing muzzles swung around with caddies, so I'll probably make a bright green muzzle cap (should always be unloaded, but I'll include a thick steel disc inside the end for extra safety).





I have been having fun making parts at my desk, using my 3D printer. Easier than driving the 10 miles to my shop to make metal parts. I will be back in the shop tomorrow, replacing some of the steel with aluminum and trying a rifle weight of about 18lb next.

[Gear_Junkie]

I shot my QB58 at last Sunday's CASA FT match. I had the weight up to 21 lbs. I shot well enough but I really did not like dealing with that much weight. Very light recoil but balance is not yet right.

I was also testing my new scope wheel (with extra data columns). And my built in caddy/handle. Both worked well. I usually case my guns between lanes but am looking for ways to speed things up. But I don't like seeing muzzles swung around with caddies, so I'll probably make a bright green muzzle cap (should always be unloaded, but I'll include a thick steel disc inside the end for extra safety).





I have been having fun making parts at my desk, using my 3D printer. Easier than driving the 10 miles to my shop to make metal parts. I will be back in the shop tomorrow, replacing some of the steel with aluminum and trying a rifle weight of about 18lb next.

Scott, I think that wheel is missing a column for "PHASE OF THE MOON" so that you can account for the effect of the moons gravity on the pellets 

[Scotchmo]

The QB58 shot OK at the last match with the RAM mount/riser attached but I did not actually use it as all targets were easily visible and no severe angles.

Today, I decided to actually try it in the backyard with different adjustment settings - not good!

The POI would shift significantly if the riser was lowered any significant amount. 1.5moa when lowered half way down. I had suspicions that there would be some difference but did not expect that much,

The mount works fine if you re-zero after each adjustment, but that defeats it's purpose for me. I'm going to have to rethink this. At this point I'm thinking of scrapping the Ram mount idea.

[DRAGON64]

Nice work, what 3D printer are you using for the work?

[Scotchmo]

Nice work, what 3D printer are you using for the work?

Anycubic Linear Delta Plus

[gokidd]

The QB58 shot OK at the last match with the RAM mount/riser attached but I did not actually use it as all targets were easily visible and no severe angles.

Today, I decided to actually try it in the backyard with different adjustment settings - not good!

The POI would shift significantly if the riser was lowered any significant amount. 1.5moa when lowered half way down. I had suspicions that there would be some difference but did not expect that much,

The mount works fine if you re-zero after each adjustment, but that defeats it's purpose for me. I'm going to have to rethink this. At this point I'm thinking of scrapping the Ram mount idea.

That seems really weird. Too much pendulum effect from the weight of that C-channel hanging down?
Bob

[Scotchmo]

The QB58 shot OK at the last match with the RAM mount/riser attached but I did not actually use it as all targets were easily visible and no severe angles.

Today, I decided to actually try it in the backyard with different adjustment settings - not good!

The POI would shift significantly if the riser was lowered any significant amount. 1.5moa when lowered half way down. I had suspicions that there would be some difference but did not expect that much,

The mount works fine if you re-zero after each adjustment, but that defeats it's purpose for me. I'm going to have to rethink this. At this point I'm thinking of scrapping the Ram mount idea.

That seems really weird. Too much pendulum effect from the weight of that C-channel hanging down?
Bob

Not really weird.

I replaced the steel C-channel with aluminum so that center rail is about 1/3 the mass now. But I added a bunch more mass to the muzzle (clamp -on shaft collars) as that is where is seems to do the most good.

Any masses attached to the gun generate a force on the gun when the gun accelerates (recoils). If you move the point of contact, or amount of contacting force on a piston gun, the POI changes. That's why a consistent hold is needed - as the gun wants to pivot about any restriction to movement, whether it be an attached mass, your hand, bipod, rest, etc.

I've decided that any attached mass must be rigid and any changes to the configuration (hamster) during a match should not change the front/back and top/bottom CG location. So I made a light weight rotating stand/bipod/hamster.

I'm narrowing in on a configuration that I will stick with for several matches. I replaced the piston seal, breech seal and main spring. I'm shooting 8.44gr at 782fps or 792fps average depending on which chronograph I use. The total gun weight when shooting is about 17.5 lb.

I designed/built an integrated caddy with a carry handle. It has a tray to hold the pellets and timer while being carried. It also has an extra long sunshade built into it. I don't like seeing exposed muzzles being swung around, so I made a magnetic muzzle cap with a steel plate inside that should stop any accidental discharge, but it's real purpose is to act as a substitute for an empty chamber indicator.

[Motorhead]

The GREEN GOBLIN lives again ..... 

Whoa !!!!

[gokidd]

Very cool, Scott H!

The GREEN GOBLIN lives again .....

Nailed the project name, Scott S!
Haaa!
B

[Scotchmo]

I think my WFTF rig is ready:


I ordered a custom size seat/bag. I made an internal structure that is mostly thin plywood, covered in felt, that comes apart and collapses for easy packing. Stuffed dimensions are 21.25" x 18.25" x 5.88":




This years WFTF world Match is in England. Even though it's the best time of the year, there is still a good chance for rain over the three day period. The bag contains a rain suit and boots just in case:

[gokidd]

Love it!
Go get 'em, Scott!!!!
Bob

[Scotchmo]

I've been dealing with a lot of issues with the QB58 over the last three or four months. Too many years of heavy use and multiple rebuilds. I decided to switch to PCP. The trip to the worlds is also a vacation so I already switched my entry to PCP, with hopefully less to worry about.

If I switch back to piston at some point, I'll probably look at replacing the piston and maybe the compression cylinder in the QB. Or maybe switch to a different gun.

For now I'm playing with a Diana Skyhawk, and it's very accurate (after installing an LW barrel). I'll be using a lot of the same stuff I've been working on (seat, scope, rain gear, etc.). Initially in Open, and then reduce to 12fpe for WFTF.

[gokidd]

Sounds cool, Scott.
Go get 'em!
Bob

[Scotchmo]

I finished out the year with my Skyhawk in Hunter Division. I did enjoy it and plan on sticking with the Skyhawk for some time. But I did buy a TX200, so I may be shooting in some of the piston classes again next year.